The equivalent propagation method adopts a variable propagation velocity in lightning location, minimizing the location error caused by various factors in the long-range lightning location network. To verify the feasibility of this method, we establish a long-range lightning location network in China. A new method is used to extract the ground wave peak points of the lightning sferics and is combined with the equivalent propagation velocity method for lightning location. By comparing with the lightning data detected by the lightning locating system called advanced direction and time-of-arrival detecting (ADTD) that has been widely used for tens of years in China, the feasibility of this method is initially verified. Additionally, it is found that the relative detection efficiency of our long-range lightning location network can reach 53%, the average location error is 9.17 km, and the detection range can reach more than 3000 km. The equivalent propagation method can improve the average location accuracy by ~1.16 km, compared with the assumed light speed of lightning-radiated sferic from the lightning stroke point to the observation station. The 50th percentile of the equal propagation velocity is 0.998c, which may be used in the long-range lightning location networks.

Mixed‐phase stratiform clouds contain numerous liquid, mixed‐phase, and ice clusters, quantifying the cluster scales is potentially helpful to improve the parameterizations of microphysics and radiation models. However, the scales of hydrometeor clusters at different levels of stratiform clouds are not well understood. In this study, using airborne measurements and a large eddy simulation, we show that turbulence plays an important role in controlling the clusters with length of a few hundred meters, while the scales of larger clusters have stronger vertical variations from cloud base to top. The liquid clusters are the largest near the cloud top, while the lengths of ice clusters decrease from cloud base to top. The lengths of mixed‐phase clusters depend on the glaciation process, a faster glaciation results in smaller mixed‐phase clusters. The results improve our understanding on how the liquid and ice are mixed at different levels in stratiform clouds.

Aerosol and secondary ice production (SIP) processes are both vital to charge separation in thunderstorms, but the relative importance of different SIP processes to electrification under different aerosol conditions is not well understood. In this study, using the Weather Research and Forecasting (WRF) model, we investigate the role of four different SIP processes in charge separation with different aerosol concentrations, including the rime splintering (RS), the ice–ice collisional (IC) breakup, shattering of freezing drops (SD), and sublimational breakup (SK). It is found that as the aerosol concentration increases, more but smaller cloud droplets can be lofted to mixed-phase regions. The warm-rain process is suppressed, and the declined raindrop concentration leads to fewer graupel particles. In a clean environment (aerosol concentration <1000 cm⁻³), the SD process is the most important to ice production between 0 and −10 °C, while in a polluted environment (aerosol concentration ≥2000 cm⁻³), the RS process contributes the most between 0 and −10 °C. The IC process is important between −10 and −20 °C. The SIP processes and the increase in aerosol concentration both enhance the noninductive charging rate. However, aerosol and SIP processes have opposite impacts on the charging reversal, which implies they play different roles in controlling the charge structure. In a clean (polluted) environment, the SD (RS) process has the greatest effect on the charge structure. Both the SIP processes and the increase in aerosol concentration enhance the electric field, but the enhancement in the flash rate induced by increasing aerosol concentration is much greater than SIP.

This paper analyzes the temperature, cloud type, and life stage dependencies of phase partitioning in mixed-phase clouds spanning tropics, midlatitudes, and the Arctic, using data from ground-based remote sensing measurements in Alaska and aircraft measurements from three field campaigns. The results show: (1) The liquid fraction in Arctic stratiform clouds decreased from 1 to 0.6 between 0 °C and −30 °C and was lower in spring because of the higher dust occurrence in Barrow, Alaska; (2) In wintertime orographic clouds, the liquid fraction was greater than 0.8; (3) Phase partitioning in convective clouds varied significantly with life stages. In the developing stage, it decreased from 1 to 0.3 between −5 °C and −15 °C, indicating rapid ice generation, while at the mature and dissipating stages, the liquid fractions were lower; (4) The stratiform regions of mesoscale convective systems were dominated by ice, with liquid fractions lower than 0.2; and (5) The variability of phase partitioning varied for different cloud types. In stratiform clouds, liquid dominated at warm temperatures. As the temperature decreased, an ice-dominated region was more frequently observed, while the occurrence of the mixed-phase region remained low. For convective clouds, the variability of phase partitioning was controlled by continuous glaciation with decreasing temperature and life cycle.